Reappraisal of clinical outcome in adult medulloblastomas with emphasis on patterns of relapse

Medulloblastoma in adults: an analysis of clinico-pathological, molecular and treatment factors

BACKGROUND

Medulloblastoma is a highly malignant, embryonal tumor, which is rare in adults, and shows distinct clinical, histopathological, molecular and treatment response features.

METHODS

We retrospectively investigated 44 adults (age 17-48 years) with a histological diagnosis of medulloblastoma, and in 23 immunohistochemistry was used to identify the molecular subgroups. We analyzed demographic, diagnostic, therapeutic and cognitive data, and correlated with PFS (progression-free-survival) and OS (overall survival).

RESULTS

We observed a male prevalence and a median age of 31 years. Symptoms at onset were related to infratentorial location, while myeloradicular and/or cranial nerve involvement was rare. Histological examination showed the classic variant in 75% of patients, the desmoplastic/nodular in 23% and the anaplastic in one. As for molecular diagnosis, 17 patients were SHH and 6 non-WNT/non-SHH (5 group 4 and 1 group 3), while no WNT subgroup was found. The SHH subgroup had a prevalence of high-risk patients and leptomeningeal involvement. Patients underwent gross total or subtotal/partial resection, and craniospinal irradiation, followed in 20 cases by adjuvant chemotherapy. Median OS and PFS were 16.9 and 12 years, respectively. Metastatic disease at presentation and subtotal/partial resection were associated with worse prognosis, while the addition of chemotherapy did not yield a significant advantage over radiotherapy alone. Cognitive impairment in long-term survivors was limited and late relapses occurred in 15% of patients.

CONCLUSIONS

Future studies with adequate sample size and long-term follow-up should prospectively investigate the role of surgery and adjuvant therapies across the different molecular subgroups to see whether a personalized approach is feasible.

Prognostic factors related to overall survival in adolescent and young adults with medulloblastoma: a systematic review

Background

Medulloblastoma is a rare diagnosis among adolescents and young adults (AYA). Though prognostic factors and treatment are well characterized among children with medulloblastoma, equivalent data for AYA are sparse. We conducted a systematic review to identify predictors of survival among AYA with medulloblastoma.

Methods

We searched for primary studies of AYA (age 15–39 at diagnosis) with medulloblastoma in high-income countries within OVID MEDLINE, EMBASE, and EBM Reviews-Cochrane library databases from inception to August 2020. Patient demographics, primary outcomes, and univariate and multivariable data on all prognostic factors were collected from included studies. Prognosticators were characterized as patient, disease, or treatment-related.

Results

We identified 18 articles. 5-year overall survival ranged between 40% and 89%, while disease-free survival ranged from 49% to 89%. Study quality was low as assessed by the Quality in Prognostic factor Studies tool. Though meta-analyses were not possible due heterogeneity, narrative summaries suggested that lower disease burden, superior postoperative functional status, and higher doses and larger fields of radiation were associated with improved survival. Reported chemotherapy regimens were heterogeneous in timing, agents, and relationship with radiation, precluding meaningful comparisons. Only one study included molecular subgroups for analysis, with the majority (76.5%) of tumors classified as Sonic Hedgehog (SHH).

Conclusions

Prognostication and treatment of AYA medulloblastoma is limited by a dearth of primary evidence and lack of specificity for patients aged 15–39. Dedicated prospective trials to delineate the benefit of various chemotherapy and radiation regimens are required in this population to identify prognosticators and ideal treatment regimens.

Radiotherapy for Adult Medulloblastoma: Evaluation of Helical Tomotherapy, Volumetric Intensity Modulated Arc Therapy, and Three-Dimensional Conformal Radiotherapy and the Results of Helical Tomotherapy Therapy

Introduction

All adult medulloblastoma (AMB) patients should be treated with craniospinal irradiation (CSI) postoperatively. Because of the long irradiation range, multiple radiation fields must be designed for conventional radiotherapy technology. CSI can be completed in only one session with helical tomotherapy (HT). We evaluated the dose of HT, volumetric intensity modulated arc therapy (VMAT), and three-dimensional conformal radiotherapy (3D-CRT) of AMB and the results of 5 cases of AMB treated with HT.

Methods

Complete craniospinal and posterior cranial fossa irradiation with HT, VMAT, and 3D-CRT and dose evaluation were performed. And results of 5 cases of AMB treated with HT were evaluated.

Results

A large volume of tissue was exposed to low dose radiation in the organs at risk (OAR), while a small volume was exposed to high dose radiation with HT. The conformity and uniformity of the targets were good with HT and VMAT, and the volume of targets exposed to high dose with VMAT was larger than that of HT. The uniformity of 3D-CRT was also good, but the dose conformity was poor. The main toxicity was hematologic toxicity, without 4th-degree bone marrow suppression. There was 3rd-degree inhibition in the white blood cells, hemoglobin, and platelets. The three female patients suffered menstrual disorders during the course of radiation. Two female patients with heavy menstruation suffered 3rd-degree anemia inhibition, and 2 patients suffered amenorrhea after radiotherapy. Although menstrual cycle was normal, the third patient was not pregnant.

Conclusion

CSI with HT is convenient for clinical practice, and the side effects are mild. With good conformity and uniformity, VMAT can also be used for selection in CSI. For poor conformity, 3D-CRT should not be the priority selection for CSI. In female patients, the ovaries should be protected.

Chemotherapy increases long-term survival in patients with adult medulloblastoma--a literature-based meta-analysis

BACKGROUND

Adult medulloblastoma is a potentially curable malignant entity with an incidence of 0.5-1 per million. Valid data on prognosis, treatment, and demographics are lacking, as most current knowledge stems from retrospective studies. Surgical resection followed by radiotherapy are accepted parts of treatment regimes; however, established prognostic factors and data clarifying the role of chemotherapy are missing.

METHODS

We investigated 227 publications from 1969-2013, with 907 identifiable, individual patients being available for meta-analysis. Demographic data, risk stratification, and treatment of these patients were similar to previous cohorts.

RESULTS

The median overall survival (mOS) was 65 months (95% CI: 54.6-75.3) , the 5-year overall survival was 50.9% with 16% of the patients dying more than 5 years after diagnosis. Incomplete resection, clinical and radiological signs for brainstem infiltration, and abstinence from radiotherapy were predictive of worse outcome. Metastatic disease at tumor recurrence was identified as a new prognostic factor, while neither metastasis at initial diagnosis nor desmoplastic/classic histology was correlated with survival. Patients receiving chemotherapy first-line survived significantly longer (mOS: 108 mo, 95% CI: 68.6-148.4) than patients treated with radiation alone (mOS: 57 mo, 95% CI: 39.6-74.4) or patients who received chemotherapy at tumor recurrence. This effect was not biased by tumor stage or decade of treatment. Importantly, (neo)adjuvant chemotherapy also significantly increased the chance for long-term survival (>5 y) compared with radiotherapy alone or chemotherapy at tumor recurrence.

CONCLUSIONS

This meta-analysis clarifies relevant prognostic factors and suggests that chemotherapy as part of first-line therapy improves overall survival and increases the proportion of patients with long-term survival.

Radiotherapy for adult medulloblastoma: Long term result from a single institution. A review of prognostic factors and why we do need a multi-institutional cooperative program

AIM

We retrospectively analyzed our Institution experience with these patients. The endpoints of the analysis were overall survival (OS), disease-free survival (DFS), local control (LC), metastasis free survival (MFS); results were compared with the literature.

BACKGROUND

Medulloblastoma in adult patients is a very rare disease; the 5 and 10-year overall survival rates range between 33-78% and 27-56%, respectively. The collection of more clinical data is strongly needed.

MATERIALS AND METHODS

From September 1975 to October 2006, we treated 16 adult patients (9 males and 7 females) with a histological diagnosis of medulloblastoma. Acute and late toxicities were scored according to RTOG toxicity scale. Karnofski performance status (KPS) and neurological performance status (NPS) pre- and post-RT were reported. Median age was 27 years (range 18-53 years). All the patients received cranio-spinal irradiation, two patients were also given chemotherapy. Median follow-up period was 121.5 months.

RESULTS

In January 2014, 10/16 patients were alive without evidence of disease, 6/16 died with progressive disease (1 local and spinal, 3 spinal and 2 extraneural). Ten-year LC, OS, DFS, MFS were, respectively, 84%, 67%, 60% and 59%. Univariate analysis shows that gross total resection is associated with better survival. No acute or late G3-G4 toxicity was observed.

CONCLUSIONS

This experience and the analysis of the literature confirm the efficacy of postoperative RT but also the need of large datasets to better define prognostic factors and the possible role of the association of chemotherapy.

Central nervous system cancers

Primary and metastatic tumors of the central nervous system are a heterogeneous group of neoplasms with varied outcomes and management strategies. Recently, improved survival observed in 2 randomized clinical trials established combined chemotherapy and radiation as the new standard for treating patients with pure or mixed anaplastic oligodendroglioma harboring the 1p/19q codeletion. For metastatic disease, increasing evidence supports the efficacy of stereotactic radiosurgery in treating patients with multiple metastatic lesions but low overall tumor volume. These guidelines provide recommendations on the diagnosis and management of this group of diseases based on clinical evidence and panel consensus. This version includes expert advice on the management of low-grade infiltrative astrocytomas, oligodendrogliomas, anaplastic gliomas, glioblastomas, medulloblastomas, supratentorial primitive neuroectodermal tumors, and brain metastases. The full online version, available at NCCN. org, contains recommendations on additional subtypes.

Identification of cell surface targets through meta-analysis of microarray data

High-resolution image guidance for resection of residual tumor cells would enable more precise and complete excision for more effective treatment of cancers, such as medulloblastoma, the most common pediatric brain cancer. Numerous studies have shown that brain tumor patient outcomes correlate with the precision of resection. To enable guided resection with molecular specificity and cellular resolution, molecular probes that effectively delineate brain tumor boundaries are essential. Therefore, we developed a bioinformatics approach to analyze micro-array datasets for the identification of transcripts that encode candidate cell surface biomarkers that are highly enriched in medulloblastoma. The results identified 380 genes with greater than a two-fold increase in the expression in the medulloblastoma compared with that in the normal cerebellum. To enrich for targets with accessibility for extracellular molecular probes, we further refined this list by filtering it with gene ontology to identify genes with protein localization on, or within, the plasma membrane. To validate this meta-analysis, the top 10 candidates were evaluated with immunohistochemistry. We identified two targets, fibrillin 2 and EphA3, which specifically stain medulloblastoma. These results demonstrate a novel bioinformatics approach that successfully identified cell surface and extracellular candidate markers enriched in medulloblastoma versus adjacent cerebellum. These two proteins are high-value targets for the development of tumor-specific probes in medulloblastoma. This bioinformatics method has broad utility for the identification of accessible molecular targets in a variety of cancers and will enable probe development for guided resection.

Preponderance of sonic hedgehog pathway activation characterizes adult medulloblastoma

Medulloblastoma (MB) represents approximately 4% of adult brain tumours, and as such is a poorly studied disease. Although many adult MB are treated using paediatric MB protocols, the reported outcomes are inferior to those observed in children. It remains unclear whether biologic differences underlie these clinical observations. We investigated the molecular characteristics of 31 adult MB. Twelve and 19 adult MB were respectively examined using Affymetrix-HG-U133-plus-2.0-genechips and immunohistochemical analyses. 26/31 (84%) of adult MB examined by gene expression and/or immunohistochemical analysis showed evidence of sonic hedgehog (SHH) pathway activation. A comparison of adult and paediatric MB showed that most adult tumours cluster within the SHH-active subgroup of paediatric MB. The preponderance of SHH activity in adult MB tumours was also shown by positive SFRP1 immunostaining in 16/19 adult paraffin-embedded adult MB tumour blocks. A smaller proportion of adult tumours exhibited evidence of WNT pathway activation, as confirmed by nuclear β-catenin staining (9.7%; 3/31). Notably, we found PTCH1 gene mutation in 4/8 samples tested. Similar to children, adult MB has abnormalities in developmental signalling pathways including SHH and WNT. Importantly, we found a preponderance of SHH pathway activation amongst MB tumours in adults. This SHH signature does not appear to correlate with a long-term favourable outcome. Differences in molecular profiles exist between adult and paediatric SHH-driven MB and further investigations are needed to better characterize age-related molecular profiles in this subgroup.